Gas turbine engines may be used to power various types of vehicles and systems. A typical gas turbine engine includes at least a compressor, a combustor, and a turbine, and may include additional components and systems, depending on the particular end-use of the gas turbine engine. During operation of a gas turbine engine, the compressor draws in, and raises the pressure of, ambient air to a relatively high level. The compressed air from the compressor is then directed into the combustor, where a ring of fuel nozzles injects a steady stream of fuel. The injected fuel is ignited, which significantly increases the energy of the compressed air. The high-energy compressed air from the combustor then flows into and through the turbine, causing rotationally mounted turbine blades to rotate.
A gas turbine engine may be used to supply propulsion power, electrical power, and/or pneumatic power. For example, many aircraft use gas turbine engines as auxiliary power units to supply pneumatic power for various systems and functions. These systems and functions may vary, and may include the aircraft environmental control system, the cabin pressure control system, and/or main engine start (MES) air. The pneumatic power is, in many instances, provided by bleeding compressed air from a centrifugal load compressor that is driven by the turbine.
More specifically, during gas turbine engine operation, the load compressor draws in ambient air, via an air inlet, and compresses the air. A plurality of inlet guide vanes are mounted adjacent the inlet and are movable via one or more actuators. By selectively adjusting the position of the inlet guide vanes the flow rate of air entering the load compressor, and thus the flow rate of bleed air supplied to the various systems and functions, may be regulated.
Gas turbine engines, such as those described above, may be exposed to various environmental conditions, including those that may result in ice formation at the inlet to the load compressor. Ice formation on the inlet guide vanes can result in reduced airflow through the load compressor and the inability to move the inlet guide vanes. Reduced airflow through the load compressor can have various deleterious effects on compressor operation and gas turbine engine performance.
Hence, there is a need for a system and method of effectively removing ice that may have formed on gas turbine engine compressor inlet guide vanes and/or preventing, or at least inhibiting, reformation of ice on gas turbine engine compressor inlet guide vanes after the ice has been removed. The present invention addresses at least this need.